111 Objections to the Second Thesis
In re-examination by Mr Semmler QC, Mr Stuart-Smith raised essentially four reasons why the second thesis should not be adopted, those objections being based on the skid marks themselves. I granted leave to Mr Stitt QC to further cross-examine him on this issue. I shall discuss these objections separately.
(1) There are no skip skid marks on the left hand side
Mr Stuart-Smith said he could not see a left side skip skid mark corresponding with the right side skip skid marks which he highlighted blue on Exhibit E (p. 498) but later in re-examination conceded that left-sided skid marks may not have been sufficient for the Police to be able to detect and record them. He said that that was "the most likely explanation" (p. 506). In further cross-examination he was shown Exhibit V, a blown up copy of photograph Exhibit B7 which shows on the on the left side of the skip skid marks a black parallel line which appears to me to show 2 skid marks, one on top of the other, a continuous light black line and a darker intermittent line, which has been marked with a continuous white line of lime. This evidence was given:
"Q. Do you agree with me that, looking at Exhibit V, it's not accurate to say that that line is a continuous skid mark, is it?
A. Look, you can't really tell whether it's continuous or not there. I agree with you it's not accurate to describe it as having a continuous density of blackness.
Q. What it does show is that there is varying density of blackness in short lengths down the length of the line as marked with chalk.
A. Correct.
Q. Entirely consistent with the pressure of the wheel being down and then up and then down and then up. In other words, greater pressure followed by lesser pressure followed by greater pressure followed by lesser, downward pressure.
A. Yes, it would be consistent with that.
Q. That is the classic skip-skid dynamic, is it now?
A. No, the classic skip-skid would have corresponding marks- -
HH: Q. No, 'The classic skid-skip dynamic', was the question.
Stitt: Yes, I - yes
Q. That would be, do you agree, or that is, the classic skip-skid dynamic?
A. Yes."
From my examination of Exhibit V and bearing in mind this concession, I do not accept this objection as valid.
(2) The distance between the skip skid marks at cone 8 is "too close"
In re-examination Mr Stuart-Smith said:
"A. The width between the outsides of the wheels of this trailer and of most trailers of this nature is typically about 2.1 metres or so from outside wheel to outside wheel. And that's roughly about somewhere around 2 to 2.1 metres, I'd expect the width of the skip-skid marks to be. If I look at these the distance between the more continuous left side mark and the right side mark is more like 1.7 metres. It corresponds more to a line just to a right side being just over the centre line, not to the skip skid marks which are just on the left of the centre line. So that's one point that the width is much narrower than I would expect."
The line on the right hand side has been highlighted green on Exhibit E. In further cross-examination the question was raised as to whether such skip skid marks were laid down by the outer wheels or inner wheels of the trailer (pp. 510 - 515). Mr Stuart-Smith agreed that the total width of the dual wheels on one side was approximately 0.5m and that the distance between the inner surface of each of the dual wheels was approximately 1.4m (p. 514). The questioning continued thus:
"Q. So that if the point on which the skid mark was laid down by the tyre is approximately the medium point of the tyre, then the distance between the two skid marks is approximately 1.5, 1.6, is it not?
A. Yes, it could be. From between the centre of inner to the centre of inner.
Q. Which is very close to 1.7, that you said you assessed these skid marks.
A. Yes, it is very close.
Q. But you t hen went on to say that that dimension was such as to be too narrow to make it consistent with it coming from the one vehicle.
A. Yes.
Q. Do you agree with me that on the process of reasoning that we have just gone through, it is not too narrow at all, is it?
A. Yes, I went through another process of reasoning.
Q. But on the process of reasoning that you and I have just been through, it is not too narrow at all, is it?
A. Not on that process of reasoning, no."
Mr Bailey was cross-examined on this issue by Mr Semmler QC and did not agree that the distance was too narrow. He said that the marks were consistent with having been made "by the inner tyre set". In light of Mr Stuart-Smith's concession and the firm evidence of Mr Bailey, I do not accept that this objection is valid.
(3) The left hand skid marks line up with the trailer whilst the green highlighted line leads to the truck
I have already referred to the skid mark(s) highlighted green which include the skip skid marks in the first objection. There is an obvious line of skip skid marks to the left of the green line, which has been highlighted orange. There is a gap between the right side skip skid marks commencing near cone 8 highlighted blue and the commencement of the orange line of 7 metres. Mr Stuart-Smith projected the green line to beneath the truck at rest and the orange line to the left rear side of the trailer. In further cross-examination Mr Stuart-Smith gave this evidence:
"Q. Can we come now to your third reason, which is the question of continuous mark and the direction in which it runs.
A. Yes.
Q. So that I am clear, your third reason is predicated on the proposition that the left-hand continuous mark on Exhibit V is not consistent with the left-hand side wheels of the trailer.
A. Correct.
Q. And what are you saying is that the continuous mark leads up to a point which you say is not the left-hand side of the trailer. Is that accurate?
A. Yes.
Q. It's that distinction which comprises your third reason. Is that correct?
A. I can't remember what number reason it is, but it certainly comprises a reason.
Q. There were three that you gave and - well, I'll move on. You made it clear, I think, in your evidence that once there was impact between the car and the truck, the trailer, which is affixed at the back of the truck, would perform motions or dynamics which may be difficult to predict with certainty, because of the force of the impact. Is that correct?
A. That is correct.
Q. Is it also correct that the fact that the trailer was affixed to the back of the truck with the towbar and had no steering wheels also a factor in deciding that the movement of the trailer after the impact becomes problematic?
A. Look, I don't know that that fact that it's not steerable makes it any more or less difficult to predict the type of marks that it would have left on the road. That's really what we're talking about when we're saying 'problematic'. I accept that the movement during and after impact means that there would be a change in forces and, consequently, tyre marks could well be different and vary.
Q. It's plain, however, that there were considerable dynamic forces in operation after the impact between the truck and the car, as evidenced in photographs B7 and B8.
A. I would agree with that.
Q. Those considerable dynamic forces involved the following. After the impact, the truck jack-knifed or slewed around with the rear of the truck going clockwise and the front of the truck similarly going clock-wise, finishing up in a position as shown on photographs 7 and 8.
A. That's correct
Q. Similarly, the forces that were generated in the collision indicated or dictated that the trailer remained, at rest, facing north.
A. Yes.
Q. But in order for the trailer to reach that position and the truck to reach that position, you agree that the rear of the truck had, after impact, to move to the left?
A. Yes, rotate clockwise. It actually - -
Q. I'm just asking you, do you agree that, after impact, the rear of the truck moved to the left?
A. That's slightly ambiguous, really. Relative to its centre of mass, it has certainly moved to the left.
Q. That's what I'm asking you about. Relative to its centre of mass, the rear of the truck moved to the left.
A. Yes.
Q. Because of the attachment by the towbar, do you agree that the front of the trailer would similarly be moved in that direction?
A. Yes.
Q. And because the truck continued to rotate and reach the point as shown in Exhibits 7 and 8, the front of the trailer would be pulled back to the right, into the position where it came to rest, as shown in 7 and 8?
A. I don't know that there's any sort of significant degree of pulling back. The trailer was pretty well gone straight ahead, but maybe with the slight deviation to its left, whereas - -
Q. I am suggesting to you that there was this two-directional movement of the trailer after the impact, namely, initially to the left, and then either to the right or back to a straight ahead position where it reached at rest. Do you agree with that?
A. To a very, very slight extent, I do.
Q. Let me suggest to you that that is precisely what the enthusiastic Sergeant Kraefft chalked on the road, a series of skid marks which show the trailer deviating to the left and then coming back to the right. And please look at Exhibit V, if you need to do so.
A. Yes, he has, to a very slight extent. That exaggerates the degree because of the telephoto nature. If I look at the photogrammetry plan, I can see the same deviation. It's more of a slight deviation to the left and then a straightening really, rather than a - -
Q. You see, what I'm asking you about is the commencement of the deviation to the left by the trailer. That would occur, would it not at impact or immediately after impact.
A. Pretty close, yes. Pretty well at impact or just after.
Q. So that the fact those skid marks in photograph B7 deviate away to the left and then come back slightly to the right is consistent with the passage of the trailer after impact.
A. Yes, it is, yes.
Q. And that would explain, would it not, the two kinds of skid marks which Kraefft has chalked in; namely, the dotted ones down near cone 9 which lead around to the left and then back to the right.
A. Explain - I'm not sure what you mean - the two types, it explains those and what's the other type?
Q. To the left - the dotted chalk marks to the left of the continuous line which plainly move to the left and then come back to the right, that would explain that dynamic movement, would it not?
A. Yes, it would.
Q. In other words what caused it was the force of the impact.
A. Yes, and braking.
Q. What brought it back was the jack-knifing effect of the truck as a consequence of the impact.
A. Yes, the dynamics of the post-impact movement, yes.
Q. With those dynamics as roughly drawn on the road in chalk, would you agree, that after there is impact it becomes difficult then to be precise about what is continuous and what is broken skid marks as evidence by the chalk, in evidence V?
A. Yes, I would agree with that."
Mr Bailey was cross-examined on the same issue. On a copy of Exhibit B7 printed in his report, he marked the green line X and the blue line Y.
"Semmler: Q. Would you agree the line you've marked with an 'X', after curving slightly continues to a point which is the place of rest of the trailer? Indeed, it may even go beyond that, but it certainly appears to be heading towards the driver's side rear wheels of the trailer.
A. I agree that the white line that's shown is a prolongation of what I've marked as X. It curves to the left back to the right and it appears to terminate near the rear axle of the trailer at rest on the right side. But absent - but without being able to see photographs of the marks on the road before they were marked, given that there are so many marks on this photograph, there's equally a number of lines which travel from tyre mark X to the left side. Now, I know that at some point pre-impact all the tyres of the vehicle would be travelling along essentially coincident paths.
Q. Thankyou for that. But look all I was asking - I wasn't asking for a justification of your analysis. I was simply asking whether you conceded that the line marked with the X continued on and appeared to at least go towards the driver's side rear wheels of the trailer, if not beyond that.
A. I don't accept that because - -
Q. You don't accept that?
A. - - that not what I marked with X. With X I was really talking about different things.
Q. All I'm asking you to do is have a look at the photograph and agree that the line you've marked with an X appears - it goes straight - or relatively straight for a period, and then itself lines up with what we can see heading off into the distance in a slight S shape a line which ends - or appears to go to the driver's side trailer wheels.
A. I agree that the white line visible in Exhibit V does that, but I marked with an X the tyre mark on the road, as I discussed it, and I can't tell from Exhibit V where that tyre mark goes.
Q. Wouldn't you agree that it looks likely that the slight S is a continuation of the tyre mark which has been chalked in and is now X on your diagram?
A. No, it doesn't look likely because the tyres from the left side of the truck must have moved to a similar position laterally down the road. See, all the left-side wheels were originally going along - in a broad sense - all the left-hand wheels of all axles, truck and trailer, were all going past X or thereabouts. At some point post impact the left wheels of the truck which continued to skid move so that they are now in front of the right wheels of the trailer. But there are other white lines in Exhibit V which diverge from near the tyre mark X and go to the left side of the trailer.
Q. You believe that those lines diverging to the left are the lines created by the trailer tyres, don't you?
A. Yes, I do.
Q. But what I'm suggesting to you is that the line marked X which I also suggest to you continues in a slight S shape up to at least the driver's side rear wheels of the trailer was probably created by skidding wheels of the truck itself rather than the trailer. What do you say about that?
A. I'm sorry could you repeat that. I may have misinterpreted what you said.
Q. The line marked X.
A. Yes.
Q. The line marked X was probably created by the skidding tyres of the truck.
HH: I think you mean the line marked Y, don't you?
Semmler: No, your Honour, I mean X.
Q. Do you accept that or not?
A. I'm not sure I know what I am being asked here. I just need to - -
Q. Can you see - -
A.- - clarify things.
Q. Can you see the line with the X on it?
A. Yes.
Q. Is it possible that was created by the truck and not the trailer?
A. Yes, that's a possibility. It's a low, - I discussed that, and it's a low probability. And it's a high probability that the intermittent tyre mark - that's the tyre mark that I marked with an X - was created by the trailer. Now, that's near the point X, once it progresses. I just think - you need to be very careful what can be drawn from Exhibit V.
Q. What I'm suggesting to you is given that the marks to the left of line X, which you believe were created by the tyres of the trailer post impact, given their position, as against what appears to be the continuation of line X, it is most unlikely that line X represents the trajectory of the left-hand side of the trailer?
A. I don't agree with that.
Q. Because if it leads up to the right-hand wheel of the trailer, and it's all the one marking, it's undoubtedly not the left-hand side of the trailer, is it?
A. I don't believe it's all the one marking; that's what I'm trying to say. And I just don't think there's the information in Exhibit V to make that."
Bearing in mind Mr Stuart-Smith's concessions and Mr Bailey's assertions it is very difficult to draw any firm conclusion about this objection. It does not of itself cause me to reject the second thesis, if there be other grounds for its adoption.
(4) The 7 metre gap between the blue and orange skid marks
In re-examination, Mr Stuart-Smith said this:
"Q. Is it possible that you can have, in effect, a skip skidding mark created by the driver's side wheel at one point, and then at a point further north, as it's proceeding north, the passenger side trailer wheels create that line which is at the western most extremity of this photo, Exhibit V?
A. Well, I would expect if it was skip skidding due to just the application of brakes, that there could be a change in - it could happen on one side at a different location from the other side. But I would still expect it to be within reasonable proximity. The actual gap between the start of the skipping on the right and the actual start of the left side tyre marks which I have drawn in orange is about seven and a half metres, and would think that would be unusually long for skipping to occur without skipping to occur on the other side."
In discussing the third objection, I referred to this gap as that between the blue line and the orange line. This objection misses the mark as the second thesis is based on there being skip skid marks on the green line at the same level as the undoubted blue skip skid marks. At p. 522.16 Mr Stuart-Smith accepted that this was not a valid objection to the thesis.